1. Field of the Invention
This invention relates to wheel structures and in particular to means for selectively locking wheels, such as cart casters.
2. Description of the Prior Art
It is desirable to provide means for locking caster wheels against rotation such as where the caster wheels are used on trucks and the like. One form of lock lever caster is illustrated in U.S. Pat. No. 1,137,329 of J. A. Johnson. As shown therein, the locking means utilizes a cam forcing a broad surface of a lock lever against a side of the caster roller so as to bind the roller throughout an extended area.
In U.S. Pat. No. 1,863,349 of William H. Noelting et al, a brake caster is provided having a clutch member carried by the wheel and a second clutch member carried by one of the ears of the yoke supporting the wheel. A nut is provided on the wheel supporting bolt which includes radially arranged grooves with a lever being seatable in one of the grooves.
In Edward H. Schultz, Jr. U.S. Pat. No. 2,147,064, a caster wheel brake is disclosed having a pedal means permitting operation of the brake by a person's foot. The brake includes a brake arm and a cam lever which is rocked in effecting the braking action.
In John F. Kostolecki et al U.S. Pat. No. 2,905,275, a caster brake is disclosed having cams arranged to lower a brake member to bring a wheel braking portion into engagement with the wheel.
In Edwin T. Clinton et al U.S. Pat. No. 3,070,828, a removable caster lock is disclosed wherein means are provided for locking the caster wheels at right angles to the direction of movement of the article being supported to effectively brake the article.
In U.S. Pat. No. 3,467,981, of Joseph E. Peter, a caster brake is disclosed having plungers which are displaced inwardly by a washer to effect axial displacement of the caster wheel causing it to frictionally engage the opposite leg of the caster fork to effect the desired braking action.